Compliance Assessment of Welsh River SACs Against Phosphorus Targets

Changes to guidance from the Joint Nature Conservation Committee have led us to review the conservation objectives for river Special Areas of Conservation (SACs) in Wales.

Phosphorus targets have been substantially tightened. We are in the process of amending our freshwater SAC Core Management Plans to incorporate the new targets.

This report assesses compliance with the revised phosphorus targets for Welsh river SACs.

Phosphorus concentration data were extracted from the NRW water quality database for a three-year period from January 2017 to December 2019 for all sample points within water bodies in the nine SACs designated for one or more river features. These were:

  • Afon Eden – Cors Goch Trawsfynydd
  • Afon Gwyrfai a Llyn Cwellyn
  • Afon Teifi
  • Afon Tywi
  • Afonydd Cleddau
  • Meirionnydd Oakwoods and Bat Sites (the Afon Glaslyn)
  • River Dee & Bala Lake
  • River Usk
  • River Wye

Each river was divided into water bodies (river sections). In total, 125 water bodies were in scope. A thorough quality assurance process was carried out on the data.

107 water bodies were assessed, 39% passed the new targets and 61% failed. Most failing water bodies were in mid and south Wales.

Find updated phosphorus targets for 2022


The report identifies a number of responses and recommendations to tackle phosphorus failures in our protected rivers. Working with Welsh Government and stakeholders, we will seek to address these to improve the quality of our rivers. 

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